Radiofrequency Ablation

What is an Ablation?

In patients who are troubled by palpitations causing rapid heart rates a cardiac electrophysiology study is usually performed to determine the mechanism. Once the mechanism has been determined then the next method of curing the abnormal circuit is then contemplated.

How is it done?

Most abnormal rhythms can be cured with a high degree of success (approximately 95%) using a specialized catheter which can be positioned at the site of the abnormality and then using radiofrequency energy the distal electrode tip of that catheter can be heated up to 65°C and with that will cause a 5mm scar at the site of the abnormal focus and will ablate the electrical activity and arrhythmogenic potential of that focus which will heal into a dense scar. The success rates for practically all supraventricular tachycardias is in the order of 95% with a very low recurrence rate.

In addition the complication rate is quite low and these include perforation of the heart which may cause bleeding around the heart and require it to have the chest opened and the bleeding area stitched close – this would be unusual, bleeding and bruising at the site of entry of the catheters, and thrombosis in the leg to which the catheters have been placed 1:1000 chance. In patients where the abnormal conduction pathway is close to the normal conduction system applying radiofrequency energy at that site can cause heart block in 1:100 patients and then that patient would then up needing to have a pacemaker placed.

Generally patients with conduction pathways close to the normal conduction system will then benefit from the application of cryo-ablation where you can cryo-map initially with temperatures down to -30°C to determine if you can ablate the abnormal pathway leaving the normal conduction system intact and if so then the freezing can be further reduced to -60°C which causes irreversible tissue damage. Generally radiofrequency ablation and cryo-ablation are equally efficacious although there is much more experience with radiofrequency catheter ablation and it is much quicker to apply.

In a small percentage of patients where radiofrequency catheter ablation and cryo-ablation are not successful then one could proceed to open heart surgery with a view to surgically excising or ablating the focus.

If you have any further questions, please contact us at:

Queensland Cardiology
North Medical Suites, Green Lifts Level 3,
627 Rode Road
Chermside Q 4032
(07) 3861 5522